Claims
- 1. A process for preparing a presensitized lithographic printing plate precursor which comprises the steps of:
- (a) liquid-honing a surface of an aluminum sheet by jetting a high-pressure liquid from at least one nozzle at a high flow rate, joining a slurry containing a fine powder of an abrasive with the jetted high-pressure liquid stream, and directing the resulting mixed stream to strike against a surface of the aluminum sheet; then
- (b) electrochemically graining the surface of the aluminum sheet in an electrolyte comprising hydrochloric acid, nitric acid, or a mixture thereof and thereafter
- (c) coating a layer of a light-sensitive composition comprising (1) a diazo resin and a binder or (2) an o-quinonediazide compound on said surface.
- 2. A process of claim 1, wherein the process further includes the step of chemically etching the surface of the aluminum sheet after the step (a) but prior to the step (b).
- 3. A process of claim 2, wherein the process further includes the step of anodizing the aluminum sheet after the step (b) but prior to the step (c).
- 4. A process of claim 3, wherein the high-pressure liquid is jetted from at least one nozzle at a flow rate of from 30 to 140 m/second at a pressure of from 5 to 100 kg/cm.sup.2, and the slurry is spouted from a spout at a flow rate of from 2 to 25 m/second.
- 5. A process of claim 3, wherein the slurry contains a fine powder of an abrasive in an amount of from 5 to 80% by weight.
- 6. A process of claim 3, wherein the slurry contains a fine powder of an abrasive in an amount of from 30 to 50% by weight.
- 7. A process of claim 3, wherein the liquid honing is carried out to form an average center-line roughness of from 0.35 to 0.8 .mu.m.
- 8. A process of claim 3, wherein the chemical etching is carried out by using an etching solution comprising an acid or an alkali to etch from 0.1 to 10 g/m.sup.2 of aluminum.
- 9. A process of claim 3, wherein the process further includes desmutting the etching aluminum sheet after the chemical etching.
- 10. A process of claim 3, wherein the electrochemical graining is carried out to form a roughness having a pit depth of from 0.1 to 1.mu. and a pit diameter of from 0.1 to 5.mu..
- 11. A process of claim 3, wherein the electrochemical graining is carried out to form a roughness having a pit depth of from 0.1 to 0.8.mu. and a pit diameter of from 0.1 to 3.mu..
- 12. A process of claim 3, wherein the anodic oxidation is carried out in a 1 to 80 wt% aqueous solution of sulfuric acid, phosphoric acid or a mixture thereof, at a temperature of from 5.degree. to 70.degree. C., at a current density of from 0.5 to 60 amperes/dm.sup.2, at a voltage of from 1 to 100 v, and for a time period of from 10 to 100 seconds.
- 13. A process of claim 12, wherein the anodic oxidation is carried out to form an anodic oxidation film having a thickness of from 0.1 to 10 g/m.sup.2.
- 14. A process of claim 12, wherein the anodic oxidation is carried out to form an anodic oxidation film having a thickness of from 0.3 to 5 g/m.sup.2.
- 15. A process of claim 1, wherein the slurry contains an acid or an alkali.
- 16. A process of claim 1, wherein the liquid honing is carried out to form an average center-line roughness of from about 0.3 to 1.2 .mu.m.
- 17. A process of claim 1, wherein said electrolyte comprises 0.1 to 10 wt% hydrochloric acid, nitric acid, or a mixture thereof.
- 18. A process of claim 1, wherein said mixed stream is allowed to strike against the aluminum surface at an angle of from about 15.degree. to about 165.degree..
- 19. A presensitized lithographic printing plate precursor produced by the process of claim 1.
- 20. A presensitized lithographic printing plate precursor produced by the process of claim 2.
- 21. A presensitized lithographic printing plate precursor produced by the process of claim 3.
Priority Claims (1)
Number |
Date |
Country |
Kind |
58-128228 |
Jul 1983 |
JPX |
|
Parent Case Info
This is a continuation of application Ser. No. 631,416, filed July 16, 1984, abandoned.
US Referenced Citations (12)
Foreign Referenced Citations (3)
Number |
Date |
Country |
1557281 |
Dec 1979 |
GBX |
2047274 |
Nov 1980 |
GBX |
2060923 |
May 1981 |
GBX |
Non-Patent Literature Citations (3)
Entry |
Chemical Abstracts, #154348e, vol. 75, 1971. |
English Language Abstracts of Jap Kokai 50-136,101 & Jap Koho 79-42282, Patented 12/1979. |
Japanese Patents Report, Section Ch, vol. 79, No. 51, Jan. 25, 1980, Derwent Publications Ltd., London. |
Continuations (1)
|
Number |
Date |
Country |
Parent |
631416 |
Jul 1984 |
|